Felix

On a whim I disconnected the MAF and drove the car. No check engine light and only the slightest deterioration in the on/off throttle smoothness. Almost seemed happier to rev when the throttle's blipped in neutral. Is this to be expected? Seems to imply the MAF isn't bringing anything to the party...

Red rooster

phelix,
The DME has defaulted to using the throttle signal to keep you going. There are various sensors you could disconect and the motor would still run !
Sometimes that can make diagnosis a bit tricky .
If you start to check gas mileage , driveability, maximum power you will decide the mass meter is a pretty good thing to have working !

All the best

Geoff

Felix

Geoff, thanks for the quick response. I'm tempted to do a few 60-130 tests and see if they're any different as the car felt no different on the road. Felix

TomF

Back in the early 90's when upgrading the earlier cars to a MAF system was all the rage, Bruce Anderson coined the phrase, "cash flow sensor." This was in reference to all the guys that were wasting tons of cash on this upgrade. The MAF on the 993s does contribute to the whole package, since the 3.6 engine is really operating at close to its limits both thermally and otherwise- particularly in the TT!

Felix

My recollection is that Bruce applied that quote to hot film sensors being sold for cars that previously had mechnical flaps; the minor reduction in restriction didn't generate airflow for the buyer but cash flow for the seller...

Red rooster

phelix,
Be careful. As you know the 993tt DME uses air mass and rpm to calculate boost level ! The pressure sensor is for the dash gauge.
Just keep an eye on things if you get serious. Dont want to hear about holes in pistons next week !!!

Good luck

Geoff